Shopping Cart (0)
My Diamonds (0)
My Jewelry (0)
My Diamond Pairs (0)
Last Visited Products

Major Gem Labs Synchronizing on Important Terminology

By  , Monday, November 09, 2015

A number of important trade terms which have historic roots have been overused and misused through recent years creating consumer confusion with regard to certain key qualities. Two of these terms are related to rubies and sapphires. “Pidgeon Blood” (which is kind of a creepy term if you think about it) is in fact a very fabled and important descriptor associated with the very finest rubies. “Royal Blue” is a term applied to some of the finest blue sapphires. Two of the most important laboratories in the colored gemstone world, Gübelin Gem Lab and Swiss Gemmological Institute SSEF, have recently come together to synchronize and calibrate their usage of these two terms. By joining forces in their grading criteria they hope that other industry members will follow their lead, thereby removing some of the confusion in the market. The move may also return some of the relevance to these terms which has been significantly eroded through misuse in recent times.


Image courtesy of


According to a joint statement by the labs on November 4, the term ‘pigeon blood red’ is now defined as a red color with no apparent modifiers such as blue or brown. A tiny purplish tint is acceptable and the stone must have strong fluorescence when exposed to ultraviolet light, resulting in an "inner glow.” ‘Royal blue’ is described as saturated blue, either pure or with a slight purplish tint.


Furthermore, the two terms can only be applied to rubies and sapphires that are of “fine quality” and have not undergone any color or clarity modification including treatments such as heating or fissure filling. They must be relatively free of eye-visible or dark inclusions and show a homogeneous color distribution with vivid internal reflections.


This is not the first time an important gem term has been misused to the point where steps had to be taken to address the situation. The most notable example is the term “blue white” diamond. This term originally referred to unique subset of blue fluorescent diamonds that were completely colorless. At one point these diamonds were highly prized. But over time the term was misapplied to all fluorescent diamonds, many of which were neither rare nor desirable. The resulting consumer confusion resulted in the restrictions being placed on the use of the term. Federal Trade Commission Guide to the Jewelry Industry now contains the following statement:


It is unfair or deceptive to use the term “blue white” or any representation of similar meaning to describe any diamond that under normal, north daylight or its equivalent shows any color or any trace of any color other than blue or bluish.


While laboratory grading is essential for significant gemstones, the terminology that is used in commercial jewelry is important as well. Consumer confusion leads to lack of confidence which negatively affects the entire industry. It is good to see major laboratories collaborating to clarify and improve communication in the market.


For more specific questions ask our experts
Live chat by BoldChat

Continue shopping at

  • Follow Us
  • Sign up for our Newsletter:
    Whiteflash rating :
    4.80 Rating based on 4251 reviews. Read all testimonials
  • Contact Us
    Give us feedback Give us feedback
    Telephone 1-877-612-6770
    Outside USA 1-832-252-6770
    2150 Town Square Pl
    Sugar Land,
    TX 77479 USA
    Winner of the 2015 BBB Pinnacle Award
    Best Jeweler in Houston, Texas

Welcome to Whiteflash!

We cordially invite our Houston area clients to visit our beautiful boutique style showroom for a very special experience. Come see our A CUT ABOVE® diamonds and designer engagement rings in person and meet our friendly and knowledgeable staff of jewelry professionals.

Book your appointment now by visiting our Showroom Page where you can schedule your visit and learn more about the special venue we have created for our Houston area clients